T1 mapping: a non-invasive tool to assess the systemic right ventricle.

Ventricular remodeling leads to fibrotic changes in systemic right ventricles (RV). Native T1 mapping provides a quantitative measure in myocardial tissue characterization. The aim of our study was to correlate native T1 values of the systemic RV to function and volumetric data. Native T1 maps were generated with a single breath hold Modified Look-Locker Inversion-recovery pulse (MOLLI) sequence was acquired in the mid-ventricular short axis. Regions of interest (ROI) were drawn in both ventricular free walls, the interventricular septum (IVS), superior insertion point (SIP) and inferior insertion point (IIP) to obtain native T1 values. T1 values were compared to CMR ventricular volumes and function using Spearman correlation. The median age was 36 years (IQR 27-48 years). There were elevated mean native left ventricular (LV) T1 and IIP T1 values at 1122 ± 171 ms and 1117 ± 96 ms, respectively. RV dysfunction was associated with elevated IIP T1 (p = 0.007). Significant moderate negative correlations were seen between RV T1 and LV ejection fraction (LVEF) (r= -0.63, p = 0.01), between RV: IVS T1 ratio and LVEF (r= -0.68, p = 0.006), between LVEF and SIP: IVS T1 ratios (r= -0.54, p = 0.04), and RVEF and IIP T1 (r= -0.59, p = 0.02). Fibrosis measured by native T1 mapping in the systemic RV is most prominent in the LV wall and septal insertion point and correlates with decreased function. T1 values can be used in non-invasive imaging assessment of the RV, but further studies with larger cohorts are needed to assess ability to risk stratify and guide therapy.

Review of speckle tracking analysis to measure the size, shape, and contractility of the fetal heart in fetuses with congenital heart defects.

Evaluation of the fetal heart involves two approaches. The first describes a screening protocol in which the heart is imaged in transverse planes that includes the four-chamber view (4CV), left and right outflow tracts, and the 3-vessel-tracheal view. The second approach is a fetal echocardiogram that requires additional cardiac images as well as evaluating ventricular function using diagnostic tools such as M-mode and pulsed Doppler ultrasound. Speckle tracking analysis of the ventricular and atrial endocardium of the fetal heart has focused primarily on computing longitudinal global strain. However, the technology enabling this measurement to occur has recently been adapted to enable the clinician to obtain numerous additional measurements of the size, shape, and contractility of the ventricles and atrial chambers. By using the increased number of measurements derived from speckle tracking analysis, we have reported the ability to screen for tetralogy of Fallot, D-transposition of the great arteries (D-TGA), and coarctation of the aorta by only imaging the 4CV. In addition, we have found that measurements derived from speckle tracking analysis of the ventricular and atrial chambers can be used to compute the risk for emergent neonatal balloon atrial septostomy in fetuses with D-TGA. The purpose of this review is to consolidate our experience in one source to provide perspective on the benefits of speckle tracking analysis to measure the size, shape, and contractility of the ventricles and atria imaged in the 4CV in fetuses with congenital heart defects.

Performance and failure of right ventricle to pulmonary artery conduit in congenital heart disease.

INTRODUCTION: Surgical implantation of a right ventricle to pulmonary artery (RV-PA) conduit is an important component of congenital heart disease (CHD) surgery but with limited durability leading to re-intervention. Current single-center, retrospective, cohort study is reporting results of surgically implanted RV-PA conduits in a consecutive series of children and adults with CHD. METHODS: Patients with CHD referred for RV-PA conduits surgical implantation (October 1997 and January 2022) have been included. Primary outcome was conduit failure defined as peak gradient above 64mmHg/severe regurgitation/need for conduit-related interventions. Longitudinal echocardiographic studies were available for mixed-effect linear regression analysis. RESULTS: Two-hundred and fifty-two patients were initially included. One hundred and forty-nine patients were elegible for follow-up data collection. After a median follow-up time of 49 months the primary study endpoint occurred in 44 (29%) patients. Multivariable Cox regression model identified adult age (>18 years) at implantation and pulmonary homograft as protective factors (HR 0.11, 95% CI 0.02-0.47 and HR 0.34, 95% CI 0.16-0.74, respectively). Fever within 7 days of surgical conduit implantation was a risk factor for early (within 24 months) failure (OR 4.29, 95% CI 1.41-13.01). Longterm use of oral anticoagulant was independently associated with slower progression of peak echocardiographic gradient across conduits (mixed effect linear regression p-value 0.027). CONCLUSION: In patients with CHD, surgically implanted RV-PA conduit failure is faster in children and after non-homograft conduit implantation. Early fever after surgery is a strong risk factor for early failure. Longterm anticoagulation seems to exert a protective effect.

Clinical Factors Affecting Survival in Patients with Congenitally Corrected Transposition of the Great Arteries: A Systematic Review and Meta-Analysis.

Background: Congenitally corrected transposition of the great arteries (cc-TGA) is a defect characterized by arterio-ventricular and atrioventricular disconcordance. Most patients have co-existing cardiac abnormalities that warrant further treatment. Some patients do not require surgical intervention, but most undergo physiological repair or anatomical surgery, which enables them to reach adulthood. Aims: We aimed to evaluate mortality risk factors in patients with cc-TGA. Results: We searched the PubMed database and included 10 retrospective cohort studies with at least a 5-year follow-up time with an end-point of cardiovascular death a minimum of 30 days after surgery. We enrolled 532 patients, and 83 met the end-point of cardiovascular death or equivalent event. As a risk factor for long-term mortality, we identified New York Heart Association (NYHA) class ≥III/heart failure hospitalization (OR = 10.53; 95% CI, 3.17-34.98) and systemic ventricle dysfunction (SVD; OR = 4.95; 95% CI, 2.55-9.64). We did not show history of supraventricular arrhythmia (OR = 2.78; 95% CI, 0.94-8.24), systemic valve regurgitation ≥moderate (SVR; OR = 4.02; 95% Cl, 0.84-19.18), and pacemaker implantation (OR = 1.48; 95% Cl, 0.12-18.82) to affect the long-term survival. In operated patients only, SVD (OR = 4.69; 95% CI, 2.06-10.71) and SVR (OR = 3.85; 95% CI, 1.5-9.85) showed a statistically significant impact on survival. Conclusions: The risk factors for long-term mortality for the entire cc-TGA population are NYHA class ≥III/heart failure hospitalization and systemic ventricle dysfunction. In operated patients, systemic ventricle dysfunction and at least moderate systemic valve regurgitation were found to affect survival.

NT-proBNP in systemic right ventricles: a new cutoff level for risk stratification?

INTRODUCTION AND OBJECTIVES: The role of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in the risk prediction of patients with systemic right ventricles (sRV) is not well defined. The aim of this study was to analyze the prognostic value of NT-proBNP in patients with an sRV. METHODS: The prognostic value of NT-proBNP was assessed in 98 patients from the SERVE trial. We used an adjusted Cox proportional hazards model, survival analysis, and c-statistics. The composite primary outcome was the occurrence of clinically relevant arrhythmia, heart failure, or death. Correlations between baseline NT-proBNP values and biventricular volumes and function were assessed by adjusted linear regression models. RESULTS: The median age [interquartile range] at baseline was 39 [32-48] years and 32% were women. The median NT-proBNP was 238 [137-429] ng/L. Baseline NT-proBNP concentrations were significantly higher among the 20 (20%) patients developing the combined primary outcome compared with those who did not (816 [194-1094] vs 205 [122-357]; P=.003). In patients with NT-proBNP concentrations> 75th percentile (> 429 ng/L), we found an exponential increase in the sex- and age-adjusted hazard ratio for the primary outcome. The prognostic value of NT-proBNP was comparable to right ventricular ejection fraction and peak oxygen uptake on exercise testing (c-statistic: 0.71, 0.72, and 0.71, respectively). CONCLUSIONS: In patients with sRVs, NT-proBNP concentrations correlate with sRV volumes and function and may serve as a simple tool for predicting adverse outcomes.

Complete Transposition of the Great Arteries in the Pediatric Field: A Multimodality Imaging Approach.

The complete transposition of the great arteries (C-TGA) is a congenital cardiac anomaly characterized by the reversal of the main arteries. Early detection and precise management are crucial for optimal outcomes. This review emphasizes the integral role of multimodal imaging, including fetal echocardiography, transthoracic echocardiography (TTE), cardiovascular magnetic resonance (CMR), and cardiac computed tomography (CCT) in the diagnosis, treatment planning, and long-term follow-up of C-TGA. Fetal echocardiography plays a pivotal role in prenatal detection, enabling early intervention strategies. Despite technological advances, the detection rate varies, highlighting the need for improved screening protocols. TTE remains the cornerstone for initial diagnosis, surgical preparation, and postoperative evaluation, providing essential information on cardiac anatomy, ventricular function, and the presence of associated defects. CMR and CCT offer additional value in C-TGA assessment. CMR, free from ionizing radiation, provides detailed anatomical and functional insights from fetal life into adulthood, becoming increasingly important in evaluating complex cardiac structures and post-surgical outcomes. CCT, with its high-resolution imaging, is indispensable in delineating coronary anatomy and vascular structures, particularly when CMR is contraindicated or inconclusive. This review advocates for a comprehensive imaging approach, integrating TTE, CMR, and CCT to enhance diagnostic accuracy, guide therapeutic interventions, and monitor postoperative conditions in C-TGA patients. Such a multimodal strategy is vital for advancing patient care and improving long-term prognoses in this complex congenital heart disease.

Long-term outcomes of surgical repair for corrected transposition of the great arteries.

BACKGROUND: This study investigated the long-term outcomes of physiological and anatomical repair for corrected transposition of the great arteries and double outlet right ventricle with discordant atrioventricular connection. METHODS: This single-center retrospective study included 146 patients who underwent biventricular repair of corrected transposition of the great arteries or double outlet right ventricle with discordant atrioventricular connections from 1972 to 2023. Survival rate, freedom from reoperation, NYHA classification and incidence of systemic ventricular dysfunction in the long-term were compared between physiological repair group (PR group) and anatomical repair group (AR group). RESULTS: PR group consisted of 55 patients with median age at repair of 10.3 years. Thirty-one patients underwent conventional Rastelli procedure and 24 patients underwent atrial and/or ventricular septal defect closure. AR group consisted of 91 patients with median age at repair of 5.8 years. Seventy-two patients underwent atrial switch plus Rastelli procedure and 19 patients underwent atrial plus arterial switch operation. The 30-year survival was 63.5% in PR group and 72.3% in AR group (p=0.448). The 30-year freedom from reoperation was 71.9% in PR group and 62.2% in AR group (p=0.220). There was a significant difference in incidence of systemic ventricular dysfunction between the groups (87.5% in PR group and 35.3% in AR group: p<0.001) and long-term survivors' NYHA classification (mean NYHA class of 1.9 in PR group and 1.5 in AR group: p=0.009). CONCLUSIONS: The systemic ventricular function and general status in the long-term were significantly better in anatomical repair patients, suggesting the potential advantage of anatomical repair.

Clinical Course of TGA After Arterial Switch Operation in the Current Era.

Background: The number of patients with an arterial switch operation (ASO) for transposition of the great arteries (TGA) is steadily growing; limited information is available regarding the clinical course in the current era. Objectives: The purpose was to describe clinical outcome late after ASO in a national cohort, including survival, rates of (re-)interventions, and clinical events. Methods: A total of 1,061 TGA-ASO patients (median age 10.7 years [IQR: 2.0-18.2 years]) from a nationwide prospective registry with a median follow-up of 8.0 years (IQR: 5.4-8.8 years) were included. Using an analysis with age as the primary time scale, cumulative incidence of survival, (re)interventions, and clinical events were determined. Results: At the age of 35 years, late survival was 93% (95% CI: 88%-98%). The cumulative re-intervention rate at the right ventricular outflow tract and pulmonary branches was 36% (95% CI: 31%-41%). Other cumulative re-intervention rates at 35 years were on the left ventricular outflow tract (neo-aortic root and valve) 16% (95% CI: 10%-22%), aortic arch 9% (95% CI: 5%-13%), and coronary arteries 3% (95% CI: 1%-6%). Furthermore, 11% (95% CI: 6%-16%) of the patients required electrophysiological interventions. Clinical events, including heart failure, endocarditis, and myocardial infarction occurred in 8% (95% CI: 5%-11%). Independent risk factors for any (re-)intervention were TGA morphological subtype (Taussig-Bing double outlet right ventricle [HR: 4.9, 95% CI: 2.9-8.1]) and previous pulmonary artery banding (HR: 1.6, 95% CI: 1.0-2.2). Conclusions: TGA-ASO patients have an excellent survival. However, their clinical course is characterized by an ongoing need for (re-)interventions, especially on the right ventricular outflow tract and the left ventricular outflow tract indicating a strict lifelong surveillance, also in adulthood.

Neoaortic Regurgitation Detected by Echocardiography After Arterial Switch Operation: A Systematic Review and Meta-Analysis.

Background: Neoaortic root dilatation (NeoARD) and neoaortic regurgitation (NeoAR) are common sequelae following the arterial switch operation (ASO) for transposition of the great arteries. Objectives: The authors aimed to estimate the cumulative incidence of NeoAR, assess whether larger neoaortic root dimensions were associated with NeoAR, and evaluate factors associated with the development of NeoAR during long-term follow-up. Methods: Electronic databases were systematically searched for articles that assessed NeoAR and NeoARD after ASO, published before November 2022. The primary outcome was NeoAR, classified based on severity categories (trace, mild, moderate, and severe). Cumulative incidence was estimated from Kaplan-Meier curves, neoaortic root dimensions using Z-scores, and risk factors were evaluated using random-effects meta-analysis. Results: Thirty publications, comprising a total of 6,169 patients, were included in this review. Pooled estimated cumulative incidence of ≥mild NeoAR and ≥moderate NeoAR at 30-year follow-up were 67.5% and 21.4%, respectively. At last follow-up, neoaortic Z-scores were larger at the annulus (mean difference [MD]: 1.17, 95% CI: 0.52-1.82, P < 0.001; MD: 1.38, 95% CI: 0.46-2.30, P = 0.003) and root (MD: 1.83, 95% CI: 1.16-2.49, P < 0.001; MD: 1.84, 95% CI: 1.07-2.60, P < 0.001) in patients with ≥mild and ≥moderate NeoAR, respectively, compared to those without NeoAR. Risk factors for the development of any NeoAR included prior pulmonary artery banding, presence of a ventricular septal defect, aorto-pulmonary mismatch, a bicuspid pulmonary valve, and NeoAR at discharge. Conclusions: The risks of NeoARD and NeoAR increase over time following ASO surgery. Identified risk factors for NeoAR may alert the clinician that closer follow-up is needed. (Risk factors for neoaortic valve regurgitation after arterial switch operation: a meta-analysis; CRD42022373214).

A leadless pacemaker implantation for a patient with systemic right ventricle under ventricular assist device support.

Patients with congenitally corrected transposition of the great arteries (ccTGA) often develop complete atrioventricular block and heart failure due to the abnormal disposition of atrioventricular node and disadvantage of systemic right ventricle. These issues are managed with a pacing system and a ventricular assist device (VAD), respectively. While technological advances offer new treatment strategies, the simultaneous deployment of a leadless pacemaker and a VAD in cases of ccTGA remains unexplored. Here, we present a case of leadless pacemaker implantation for a VAD-supported ccTGA patient. The safety of a leadless pacemaker for a subpulmonary left ventricle and electromagnetic interference between devices are major concerns when implanting a leadless pacemaker; however, the current case overcomes these obstacles. There were no perioperative complications, and both devices were functioning without problems during a one-year follow up. We expect that, even in patients with cardiac complexity such as systemic right ventricle under VAD support, a leadless pacemaker could become the treatment of choice if the indication is appropriate, although careful and close follow up is needed. Learning objective: Technological advances expand treatment strategies and provide significant benefits to patients with adult congenital heart disease (ACHD). However, discussion of the combination of a leadless pacemaker and a ventricular assist device (VAD) is rare. We demonstrated the efficacy of a leadless pacemaker for a subpulmonary left ventricle in a patient with systemic right ventricle on VAD. This approach could be an option even for ACHD patients.

Molecular Pathways and Animal Models of d-Transposition of the Great Arteries.

During normal cardiovascular development, the outflow tract becomes septated and rotates so that the separate aorta and pulmonary trunk are correctly aligned with the left and right ventricles, respectively. However, when this process goes wrong, the aorta and pulmonary trunk are incorrectly positioned, resulting in oxygenated blood being directly returned to the lungs, with deoxygenated blood being delivered to the systemic circulation. This is termed transposition of the great arteries (TGA). The precise etiology of TGA is not known, but the use of animal models has elucidated that genes involved in determination of the left- embryonic body axis play key roles. Other factors such as retinoic acid levels are also crucial. This chapter reviews the animal models presenting with TGA that have been generated by genetic manipulation or with exogenous agents.

Human Genetics of Defects of Situs.

Defects of situs are associated with complex sets of congenital heart defects in which the normal concordance of asymmetric thoracic and abdominal organs is disturbed. The cellular and molecular mechanisms underlying the formation of the embryonic left-right axis have been investigated extensively in the past decade. This has led to the identification of mutations in at least 33 different genes in humans with heterotaxy and situs defects. Those mutations affect a broad range of molecular components, from transcription factors, signaling molecules, and chromatin modifiers to ciliary proteins. A substantial overlap of these genes is observed with genes associated with other congenital heart diseases such as tetralogy of Fallot and double-outlet right ventricle, d-transposition of the great arteries, and atrioventricular septal defects. In this chapter, we present the broad genetic heterogeneity of situs defects including recent human genomics efforts.

Human Genetics of Tricuspid Atresia and Univentricular Heart.

Tricuspid atresia (TA) is a rare congenital heart condition that presents with a complete absence of the right atrioventricular valve. Because of the rarity of familial and/or isolated cases of TA, little is known about the potential genetic abnormalities contributing to this condition. Potential responsible chromosomal abnormalities were identified in exploratory studies and include deletions in 22q11, 4q31, 8p23, and 3p as well as trisomies 13 and 18. In parallel, potential culprit genes include the ZFPM2, HEY2, NFATC1, NKX2-5, MYH6, and KLF13 genes. The aim of this chapter is to expose the genetic components that are potentially involved in the pathogenesis of TA in humans. The large variability in phenotypes and genotypes among cases of TA suggests a genetic network that involves many components yet to be unraveled.

[Diagnosis and treatment in a series of patients with cardiac corrected transposition of the great arteries (double discordance)]. / Diagnóstico y tratamiento en una serie de pacientes con transposición corregida de las grandes arterias (doble discordancia cardiaca).

Objective: The atrio-ventricular and ventricle-arterial double discordance (DD) or corrected transposition of the great arteries is a rare heart disease, it occurs in 0.02-0.07 of every 1,000 live newborns. The objective of the study is to describe the diagnosis, treatment and evolution of a series of patients with DD. Method: A retrospective and descriptive study was carried out, reviewing the records of patients diagnosed with DD in the last 22 years. Descriptive statistics were performed. Numerical variables were obtained using means and standard deviation and categorical variables using frequencies and percentages. Results: Thirty patients were studied in 22 years with a ratio of 1.5:1 for men, with a mean age of 20 months. The situs was solitus in 24/29 patients (82.7%). Ventricular septal defect was the most frequent lesion in 25/29 (86.2%) Tricuspid insufficiency in 70%. Four patients diagnosed with pulmonary atrial hypertension. With atrio-ventricular block 20%. One with Wolff-Parkinson-White syndrome. Surgical treatment was carried out in 70% of patients. Eight with Glenn procedure (26.6%) and 4 with Fontan surgery (13.3%). Follow-up ranged from 1 month to 17 years. Five died (16.6%). Of the 25 patients in follow-up, 18 patients (72%) had normal ventricular function, 5 with Grade II Ross classification (20%) and 2 in Grade III (8%). Conclusions: The quality of life of these patients is improving and there is still controversy in the literature about the ideal time to perform the most appropriate surgical procedure.

Objetivo: La doble discordancia auriculo-ventricular y ventrículo-arterial (DD) o transposición corregida de las grandes arterias, se presenta en 0.02-0.07 de cada 1,000 recién nacidos vivos. El objetivo del estudio es describir el diagnóstico, tratamiento y evolución de pacientes con DD. Método: Se realizó un estudio retrospectivo y descriptivo, revisando los registros de pacientes con DD en los últimos 22 años. Se realizó estadística descriptiva. Las variables numéricas se obtuvieron mediante medias y desviación estándar y las categóricas mediante frecuencias y porcentajes. Resultados: Se estudiaron 30 pacientes con una relación de 1.5:1 para el varón, con una edad media de 20 meses. El situs fue solitus en 24/29 pacientes (82.7%). La comunicación interventricular fue la lesión más frecuente en 25/29 pacientes (86.2%), insuficiencia tricuspídea en el 70%. Cuatro pacientes con diagnóstico de hipertensión arterial pulmonar. Con bloqueo atrio-ventricular un 20%. Uno con síndrome de Wolff-Parkinson-White. El tratamiento quirúrgico se realizó en el 70% de los pacientes. Con procedimiento de Glenn 8 (26.6%) y 4 cirugías de Fontan (13.3%). El seguimiento fue de 1 mes a 17 años. Cinco fallecieron (16.6%). De los 25 restantes, 18 pacientes (72%) con función ventricular normal, 5 con clasificación de Ross grado II (20%) y 2 en G III (8%). Conclusiones: La calidad de vida de estos pacientes está mejorando, aún existe controversia sobre el momento ideal para realizar el procedimiento más adecuado quirúrgico.

High-Throughput Genomics Identify Novel FBN1/2 Variants in Severe Neonatal Marfan Syndrome and Congenital Heart Defects.

Fibrillin-1 and fibrillin-2, encoded by FBN1 and FBN2, respectively, play significant roles in elastic fiber assembly, with pathogenic variants causing a diverse group of connective tissue disorders such as Marfan syndrome (MFS) and congenital contractural arachnodactyly (CCD). Different genomic variations may lead to heterogeneous phenotypic features and functional consequences. Recent high-throughput sequencing modalities have allowed detection of novel variants that may guide the care for patients and inform the genetic counseling for their families. We performed clinical phenotyping for two newborn infants with complex congenital heart defects. For genetic investigations, we employed next-generation sequencing strategies including whole-genome Single-Nucleotide Polymorphism (SNP) microarray for infant A with valvular insufficiency, aortic sinus dilatation, hydronephrosis, and dysmorphic features, and Trio whole-exome sequencing (WES) for infant B with dextro-transposition of the great arteries (D-TGA) and both parents. Infant A is a term male with neonatal marfanoid features, left-sided hydronephrosis, and complex congenital heart defects including tricuspid regurgitation, aortic sinus dilatation, patent foramen ovale, patent ductus arteriosus, mitral regurgitation, tricuspid regurgitation, aortic regurgitation, and pulmonary sinus dilatation. He developed severe persistent pulmonary hypertension and worsening acute hypercapnic hypoxemic respiratory failure, and subsequently expired on day of life (DOL) 10 after compassionate extubation. Cytogenomic whole-genome SNP microarray analysis revealed a deletion within the FBN1 gene spanning exons 7-30, which overlapped with the exon deletion hotspot region associated with neonatal Marfan syndrome. Infant B is a term male prenatally diagnosed with isolated D-TGA. He required balloon atrial septostomy on DOL 0 and subsequent atrial switch operation, atrial septal defect repair, and patent ductus arteriosus ligation on DOL 5. Trio-WES revealed compound heterozygous c.518C>T and c.8230T>G variants in the FBN2 gene. Zygosity analysis confirmed each of the variants was inherited from one of the parents who were healthy heterozygous carriers. Since his cardiac repair at birth, he has been growing and developing well without any further hospitalization. Our study highlights novel FBN1/FBN2 variants and signifies the phenotype-genotype association in two infants affected with complex congenital heart defects with and without dysmorphic features. These findings speak to the importance of next-generation high-throughput genomics for novel variant detection and the phenotypic variability associated with FBN1/FBN2 variants, particularly in the neonatal period, which may significantly impact clinical care and family counseling.

Arterial switch operation in a child with commissural malalignment and unusual coronary anatomy.

The arterial switch operation has evolved to become the treatment of choice for transposition of the great arteries and is one of the greatest success stories in congenital heart surgery. The most crucial step of the operation is the coronary artery translocation; therefore, it is of paramount importance for surgeons to know every single detail about the morphology and spatial relationships of the coronary arteries and the roots of the great vessels. However, sometimes the surgeon may face unfavourable scenarios such as major commissural malalignment and anomalous coronary artery patterns and need to be prepared to carry out a successful coronary artery translocation. Herein, we demonstrate that the trapdoor technique is useful for transferring coronary arteries in a neonate with major commissural malalignment and unusual coronary anatomy during the arterial switch operation.

Lead Extraction and Baffle Stenting in a Patient with Transposition of the Great Arteries.

This case report discusses a 42-year-old male with dextro-transposition of the great arteries (D-TGA) status post Mustard repair and sick sinus syndrome status post dual-chamber pacemaker implant, who developed symptomatic superior vena cava (SVC) baffle stenosis. He was treated with a combined pacemaker extraction and subsequent SVC baffle stenting. The case highlights the complexities of treating SVC baffle stenosis in the presence of cardiac implantable devices and demonstrates the efficacy of this combined approach. Furthermore, the authors delve into the intricacies of D-TGA, its surgical history, and the long-term complications associated with atrial switch procedures.